Alright, everyone. An endotoxin has what characteristics? So we've been talking about the 2 major classes of toxins, and endotoxins. So let's see which of these is the correct statement. Answer choice a says an endotoxin is an ab toxin. It actually is not because remember that an AB toxin is actually an exotoxin, not an endotoxin. So that is not the answer that we're looking for. Answer choice b says an endotoxin is created by gram positive bacteria. Nope. It's not created by gram positive bacteria, but gram negative bacteria. Remember that an endotoxin is a lipopoly saccharide molecule, and the class of bacteria which has extra lipids are gonna be the gram negative bacteria with that outer lipid membrane, and that is where you are going to find the endotoxins, LPS. So that's not the answer we're looking for. Answer choice c says an endotoxin is heat stable and will not denature. Remember that endotoxins include lipopolysaccharides, which are made of of lipids and carbohydrates, sugars. And lipids and carbohydrates don't technically denature, that's gonna be a term used for proteins. And if I had to guess, they probably are affected by heat in some way. So I'm gonna say that's not the correct answer either. Answer choice d says an endotoxin triggers t cells to release cytokines. It most certainly does. In fact, it triggers t cells to release an excessive amount of cytokines known as a cytokine storm. So this answer is correct. And because we know this, you could also qualify LPS and endotoxin as a super antigen since those antigens also cause cytokine storms. Okay, everyone. Let's move on to our next video.

Table of contents

1. Introduction to Microbiology3h 22m
2. Disproving Spontaneous Generation1h 18m
3. Chemical Principles of Microbiology3h 38m
4. Water1h 28m
5. Molecules of Microbiology2h 23m
6. Cell Membrane & Transport3h 28m
7. Prokaryotic Cell Structures & Functions5h 52m
8. Eukaryotic Cell Structures & Functions2h 18m
9. Microscopes2h 46m
10. Dynamics of Microbial Growth4h 36m
11. Controlling Microbial Growth4h 10m
12. Microbial Metabolism5h 16m
13. Photosynthesis2h 31m
14. DNA Replication2h 25m
15. Central Dogma & Gene Regulation7h 14m
16. Microbial Genetics4h 44m
17. Biotechnology3h 0m
18. Viruses, Viroids, & Prions4h 56m
19. Innate Immunity7h 15m
20. Adaptive Immunity7h 14m
21. Principles of Disease6h 57m

21. Principles of Disease

Endotoxin Causes Damage to the Host

Microbiology

21. Principles of Disease

Endotoxin Causes Damage to the Host

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Multiple Choice

An endotoxin:

Is an AB toxin.

Is created by gram-positive bacteria.

Is heat stable and will not denature.

Triggers T cells to release cytokines.

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Verified step by step guidance

Understand the definition of an endotoxin: Endotoxins are components of the outer membrane of Gram-negative bacteria, specifically the lipopolysaccharides (LPS). They are not proteins and do not have an AB structure like some exotoxins.

Recognize the bacterial origin: Endotoxins are associated with Gram-negative bacteria, not Gram-positive bacteria. This is a key distinction in microbiology.

Consider the heat stability: Endotoxins are indeed heat stable, meaning they can withstand high temperatures without denaturing, unlike many proteins.

Identify the immune response: Endotoxins can trigger a strong immune response. They are known to stimulate immune cells, such as macrophages, to release cytokines, which are signaling molecules that mediate and regulate immunity and inflammation.

Conclude with the correct function: Given the options, the correct function of endotoxins is their ability to trigger T cells and other immune cells to release cytokines, leading to inflammation and other immune responses.